1. Field of the Invention
The present invention relates to a wire connecting apparatus for a magnetic contactor, and more particularly, to a screw-type wire connecting apparatus for a magnetic contactor capable of providing an efficient wire connecting work.
2. Description of the Conventional Art
Generally, a magnetic contactor is a component of an electric power distribution board or a system such as a driving/controlling device of a motor. The magnetic contactor is connected to a wire connected to a system circuit, and opens and closes a circuit on the system.
The magnetic contactor has a certain lifespan according to a usage circumstance such as a usage purpose and a switching frequency. Therefore, in an electric power distribution board where a plurality of electronic contactors are installed or in a system such as a driving/controlling device of a motor where a magnetic contactor or a wire connecting of a magnetic contactor has to be changed, connecting a terminal of a magnetic contactor to an external wire connected to of the system circuit is frequently required.
The magnetic contactor is provided with a wire connecting apparatus connected to the external wire of the system. The wire connecting apparatus can be sorted into a screw-type apparatus and a lug-type apparatus.
Generally, in Asia where an external wire having a ring-shaped compression terminal or a U-shaped compression terminal is applied, a screw-type wire connecting apparatus is mainly used. On the contrary, in Europe and U.S.A, a lug-type wire connecting apparatus is mainly used.
In a magnetic contactor having a low rated current less than 25 ampere, a screw-type wire connecting apparatus is applied. In the screw-type wire connecting apparatus, in case of using an ordinary wire or a wire having a U-shaped terminal at a leading end of the wire as an external wire of the system, the external wire can be connected to the wire connecting apparatus just by releasing a screw and then by tightening the screw.
However, in the screw-type wire connecting apparatus, in case of using a wire having a ring terminal at a leading end thereof so as to be connected to a terminal of a magnetic contactor, the screw has to be completely separated from the terminal of the magnetic contactor. Then, a screw hole of the magnetic contactor terminal is aligned with a hole of the ring terminal, or a screw is inserted into the ring terminal. Then, the magnetic contactor terminal has to be coupled with the ring terminal by a screw.
In order to connect the ring terminal to the screw-type wire connecting apparatus, various tools or two workers are necessary. Accordingly, the number of wiring processes is increased, and a work productivity is lowered.